Calculate carpet padding (underpad) in square yards for your room. Enter area, choose pad thickness, and get accurate material and cost estimates.
Carpet padding (also called underpad, cushion, or underlay) sits between the subfloor and the carpet, providing comfort underfoot, extending carpet life, and improving insulation and soundproofing. Every broadloom carpet installation requires padding — it's not optional.
This calculator determines the square yards of carpet padding you need based on your room dimensions. Padding is measured the same way as carpet: in square yards. In most cases, you need the same amount of padding as carpet, but padding seams don't need to align with carpet seams, so waste is sometimes slightly lower.
Padding thickness, density, and material type vary by application. Standard residential padding is 3/8” to 1/2” thick. Thicker isn't always better — too-thick padding can cause carpet wrinkles and premature wear.
Accurate calculation of this value helps construction professionals plan projects more effectively, reduce material waste, and ensure compliance with building codes and industry standards. Tracking this metric throughout the project lifecycle helps project managers identify potential issues early and maintain quality standards from foundation to final inspection.
Padding costs $0.50–$2.00 per square yard and is a significant line item in carpet Installation. Ordering the right amount prevents waste or a second trip. Padding coverage typically matches carpet yardage but with slightly less waste. Having precise numbers at hand streamlines project planning discussions with clients, architects, and subcontractors, building trust and reducing costly misunderstandings on the job.
Area (sq ft) = Length × Width Pad Sq Yd = (Area × (1 + Waste%/100)) / 9
Result: 21 sq yd
Room area = 15 × 12 = 180 sq ft. With 5% waste: 180 × 1.05 = 189 sq ft. In square yards: 189 / 9 = 21 sq yd.
Padding absorbs the impact of foot traffic, reducing stress on carpet fibers and backing. Without padding, carpet fibers crush and mat within a few years. Proper padding can double the life of your carpet. It also insulates against cold subfloors and reduces noise transfer between floors.
Rebond is made from recycled foam scraps bonded together. It's multicolored, affordable, and available in various densities. Memory foam provides the softest feel but at higher cost. Fiber pad is thin and firm, ideal for loop-pile carpet. Rubber slab pad is the most durable and used in commercial settings.
Cut-pile carpet (plush, frieze, saxony) works best with 3/8” to 7/16” pad at 6–8 lb density. Loop-pile and Berber carpet needs thin, firm 3/8” pad at 8+ lb density. Patterned carpet benefits from higher-density pad that keeps the carpet stable.
Basement and concrete-slab installations need moisture-barrier padding with a built-in poly film. This prevents moisture from reaching the carpet and causing mold, mildew, and odor issues. Standard rebond padding is not moisture-resistant.
Standard residential padding is 3/8” to 7/16” thick. Bedrooms can use up to 1/2” for comfort. Loop and Berber carpet should always use padding no thicker than 3/8”. Too-thick padding accelerates carpet wear.
A density of 6–8 lbs per cubic foot is standard for residential use. Higher traffic areas benefit from 8+ lb density. Commercial applications use 10+ lb pad. Denser pad lasts longer and feels firmer.
Approximately, yes. Padding covers the same floor area. However, padding waste is typically 5% (less than carpet's 10%) because padding seams don't need to align with carpet seams.
Rebond (recycled foam) is cheapest and most common. Memory foam provides luxury comfort. Fiber pad is best for Berber. Rubber slab pad is used in commercial settings. Moisture-barrier pad is for basements.
Generally no. Carpet tiles (carpet squares) have a built-in backing that functions as the cushion layer. Adding padding underneath can cause carpet tiles to shift and buckle.
Rebond padding costs $0.50–$1.00/sq yd. Premium memory foam or rubber pad costs $1.00–$2.00/sq yd. Moisture-barrier padding costs $1.50–$3.00/sq yd. Many installers include basic padding in their carpet installation price.